Child resistant packaging is understood to be a important concept for preventing inadvertent access by children, for example, to potentially dangerous liquid or dry products. However, inclusion of the child resistant feature adds difficulty and frustration for the adult user when attempting to open the package. Due to the difficulty in opening child resistant packages, many persons, especially elderly adults which may also have impaired strength and dexterity, could prefer a non-child resistant package substitute. Alternatively, when dangerous products are purchased in child resistant packages by adults, the child resistant package is often not reclosed in order to defeat the child resistant feature. As a result, the danger of child poisonings may increase in the homes.
The aforementioned problems are generally recognised in the packaging industry. Attempts to deal with these problems are also disclosed in the patent literature. For example, U.S. Pat. No. 4,948,002 issued to Thornock et al. on Aug. 14, 1990 discloses a package comprising a bottle, a collar which is secured in place over the uppermost portion of the bottle and a closure which is secured to the finish portion of the bottle. The collar preferably includes a pair of spring-like pushtabs containing vertical extensions which engage interlocking teeth on the innermost surface of the closure skirt when the closure is fully assembled onto the bottle. To remove the closure, the opposed pushtabs must be manually depressed prior to applying unscrewing torque to the closure to disengage the pushtab extensions from the interlocking teeth on the closure.
The package disclosed in '002 exhibits highly improved child resistance without significantly impeding access by adults. This has been further improved in WO 92/07286, in which a package is described whose child resistance is enhanced even further without making the package more difficult to open by adults. This is achieved, if the spring-like pushtabs containing vertical extensions are, at least to a degree, preloaded so as to exert a force against the innermost surface of the closure skirt once the closure has been fully assembled onto the package.
In both documents '002 and '286 the spring-like pushtabs containing vertical extensions are part of a transition piece attached to the bottle, like the collar of '002, or may be integral part of the bottle without any transition piece. Nonetheless, the user has to use both hands to allow him/her to overcome the child resistant feature and unscrew the closure. Indeed, firstly one hand has to hold the bottle and at the same time depress the spring-like pushtabs. Secondly, the closure has to be unscrewed with the other hand. This means that both hands are needed to actually disengage said child resistant closure from the bottle, which is called in the following a "two hand operation". We found that this two hand operation is difficult for larger containers having an unwieldy external shape, especially for elderly adults having impaired manual strength and dexterity. Indeed, it is more difficult for one hand to hold a large and/or heavy container and at the same time depress the pushtabs, especially when said pushtabs are located in the upper portion of said bottle.
It is therefore an object of the present invention to provide a child resistant package which is resistant to opening by the majority of children but which, at the same time, can readily be opened by adults without the need of a two hand operation.